Synthetic resin and method of making same



Patented July 9, 1940 UNITED STATES SYNTHETIC RESIN AND METHOD OF MAKINGSAME Israel Rosenblum, New York, N. Y. I

No Drawing. Application December 19, 1936, Serial No. 116,822

10 Claims.

The present invention relates to the production of fusible, oil-solublesynthetic resins by reaction of a phenol and an aldehyde, and moreparticularly to the modification of such resins by the 5 incorporationtherein of a terpene compound,

such as terpene hydrocarbons and alcohols.

The present application is a continuation-inpart of my copendingapplications Ser. No. 538,248, filed May 18, 1931; Ser. No. 580.495,filed 10 Dec. 11, 1931; and Ser. No. 594,379, filed Feb. 20,

It is the general object of the present invention to provide an improvedand inexpensive method for the production of phenol-aldehyde resins 5which are insoluble in water but are soluble in the common resinsolvents, and are compatible with drying and non-drying oils, and withnitrocellulose, and are accordingly suitable for the manufacture ofvarnishes, lacquers, paints and U other coating compositions,particularly air drying varnishes when drying oils are used.

According to the present'invention, resins of the type indicated areobtained by incorporating therein in practically non-separable form, arela- 88 tively large proportion, up to equal amounts (referred to thephenol), and even more, of a terpene compound, preferably a high boilingcompound, such as dipentene, terpineol, and commercial mixtures ofterpene compounds, such as pine 3 oil, which contains in addition todipentene and terpineol also borneol, carvacrol, fenchyl alcohol etc.

In my British Patent 416,476 the"e is disclosed a process involving thereaction of a phenol with 88 various proportions of formaldehyde in thepresence of a terpene compound, such as dipentene or terpineol, or themixture present in pine oil, whereby oil-soluble resins are obtained inwhich the terpene compound remains in the final product to the extent ofabout 10% by weight of the phenol used, the terpene compound orcompounds not being completely expelled even upon heating to hightemperatures, indicating a probable chemical combination with thephenol- 46 formaldehyde condensate.

I have now found that much larger quantities of terpene compounds can beincorporated or combined in the resin by the use of sulphuric acid as acatalyst, at least toward the close of the re- 50 action. In this waylarger yields of resinous product are obtained with the aid of therelatively inexpensive terpenic material. Any desired catalyst may beemployed during the initial stages of the combination of the phenol andformaldehyde, after which, preferably following dehydration of thecondensate, sulphuric acid is added and the condensation continued,advantageously at higher temperatures until a fusible soluble resin isobtained which is solid at room temperatures. 5 The expression-terpenecompound as used in this specification and in the claims is to beunderstood to mean .not onlyterpene hydrocarbons, such as dipentene, butalso compounds which may be regarded as terpenic derivatives, such asthe terpene alcohols represented by terpineol, borneol, fenchyl alcoholand the like, their esters etc.

The higher homologues can be used with advantage and in general I preferto employ butyl and amyl phenols and the still higher homologues eitheralone or admixed with ordinary phenol. By virtue. of the presence of theterpenic material, the molecular proportion of formaldehyde to phenolmay be as high as 3 to 1 or more. go

When a catalyst'other than sulphuric acid is employed for the initialreaction, the process is carried out in two main stages. Thus, thephenol, aldehyde and the catalyst are reacted in the presence of asuitable terpene compound, preferg5 ably alphaterpineol or dipentene, ora mixture of these compounds, by being heated at the boiling temperatureunder a reflux or under pressure in a closed vessel to a temperature ofabout C., for about 12 to 16 hours or more. The water is so drawn oflor'distilled away, and the product may then be further condensed anddehydrated by heating it in an inert atmosphere or under vacuum to atemperature of about C. until a clear uniform resin is obtained which issemi- 35 solid or solid at room temperatures. To the product so obtainedmore terpenic material may be added to bring the total content of thelatter to the desired proportion and the reaction between the terpenicmaterial and the phenolic. condensate is then accelerated by theaddition of sulfuric acid. The sulfuric acid may be used alone oradmixed with'other acidic material, such as hydrochloric acid. Uponcompletion of the reaction a product is obtained in which an una usuallylarge quantity of terpenic material is inseparably incorporated, andmost probably chemically combined, with the phenol-formaldehydecondensate.

Any suitable catalyst may be employed during 0 the initial stages ofcondensation, including basic, neutral and acid catalysts, such assodium hydroxide, sodium carbonate, zinc oxide, zinc acetate, sulfuricacid, hydrochloric acid and other known catalysts for the reactionbetween phenol till and formaldehyde. when sulphuric acid or a mixtureof sulphuric acid and other.catalytic material is employedasaccelerating agent for the initial condensation, all the materials canbe mixed together from the start and condensed, dehydrated and furtherreacted in a continuous process. Toward the end of the reaction thesulfuric acid may be neutralized with sodium hydroxide or otherinorganicor organic base.

The terpenic material may be first partially condensed or polymerizedwith the sulfuric acid and then added to the phenol-aldehyde reactionmixture as described more in detail below.

The invention will be further described with the aid of the followingexamples which are presented for purposes of illustration and not by wayof limitation:

Example 1.-A resin derived from the interaction of:

' Parts Butylphenol 100 40% formaldehyde solution 100 Dipentene 30 (allparts by weight) with zinc acetate as catalyst (0.25 to 2 parts), byrefluxing at the boiling point for about 16 hours, drawing off theseparated water and heatingthe material to about 120 in order todehydrate it further, is treated further with 65 parts dipentene (whichbrings the dipentene proportion to the ratio'of l moi dipentene to 1 molbutyiphenol) thinned with hi-iiash naphtha for better operation, and 44grams of strong 96% sulfuric acid, which are added slowly with constantagitation so as to keep the temperature around 60 C. The stirring at 60is kept up for 2-3 hours. A two layer system is formed; the lower layer,practically all sulfuric acid, is drawn off; the upper layer isneutralized with NaOH solution, the slightly alkaline solution is againacidified with an acid to a point where an organic sodium salt (of thephenolic resin or of phenol) is no longer present. The mass is thenwashed with water and steam distilled up to a temperature of about 230C. which removes the non-combined solvents and reactants. The yield isaround 90- 100% of theoretical, based on the combined weights of thephenol and terpene. The acid number is about 20, whereas that of theresin produced in the absence of the terpene is about '70, indicatingthat the dipentene is chemically bound to the phenolic resin. This resinis compatible with drying and non-drying oils, with resins like rosin,dammar, ester gums, dry distilled fossil gum and their esters,cumarones, asphaltums, pitches, etc., with solvents such as mineralspirits, toluoi, or their mixtures, and is excellently suited for themanufactune of air-drying varnishes, nitrocellulose lacquers, etc.

Example 2.--A resin obtained from the interaction of:

Parts Phenol 47 40% CHZO solution 4'! Alpha terpineoi '77 with nineacetate as a catalyst, after condensation for hours under reflux anddrawing off of separatcd water, is subjected to the sulfuric acidtreatment, as in Example 1. The resin is then further treated as inExample 1. The product contains practically the whole alpha terpineol,corresponding to the ratio of 1 mol of terpineol to l moi of phenolchemically bound to the phenol condensate. The acid value is about 15.The

resin is oil-soluble and produces varnishes of great durability.

Example 3.-Like Example 1, except that instead of dipentene, a mixtureof dipentene and terpineol is used. A product similar to that of Example1 is obtained.

Example 4.-Like Example 2, with the exception that phenol is replaced byortho, meta or para cresol or xylenol or a mixture thereof. During theaddition of sulfuric acid, the temperature is kept below 50 0.,preferably about 30 C. An oil-soluble resin is obtained which, likethose of Examples 1-3, is solid at room temperature.

Example 5.--A resin derived from the interaction of butyiphenol,formaldehyde and dipentene in the presence of NaOH solution, wherefromthe NaOH has been removed by neutralization and washing with water, theproportions taken being:

Butylphenol 100 40% formaldehyde solution 100 Dipentene 25 is treatedfurther with 70 parts dipentene which brings up the dipentene proportionto the ratio of 1 moi dipentene to 1 mol of phenol. A uniform solutionis obtained, which can be further diluted with solvent naphtha. To thissolution 250 parts sulfuric acid of 70% strength are added slowly withvigorous stirring, care being taken to keep the temperature around 50 C.200 parts of strong sulfuric acid (96% strength) are now added slowly,the temperature being still kept at about 50 C. and the vigorousstirring continued for about 3 hours. A two layer system is formed, thelower layer containing practically all the sulfuric acid, and the upperlayer containing the resin, solvent and some'sulfuric acid. The latteris neutralized with hot 10% NaOH solution and washed with water. Thereaction in the still plastic mass is carried further by heating in aninert atmosphere with stirring to a temperature of about 230 C, in orderto expel all noncombined material, which in this case consists of allthe solvent naphtha, water and very little free dipentene andbutylphenol. In the resin thus finally obtained practically all thedipentene appears to be bound chemically to the butylphenol condensate,as none can be removed with steam at even 230 C. and the yield of resinis about 95% of the theoretical, based on the total butylphenolcondensate and dipentene. The acid value of the resin is 10-20 or evenlower. The resin is oil soluble, giving excellent alkali resistantvarnishes. which can be used as such or in conjunction with suitabiepigments for enamels and also as a binder material in the manufacturingof linoleum and similar covering materials.

Example 6.--Using the same phenolic resin as in Example 5, the amount ofadditional dipentene is increased to parts. so that the total proportionis 2 mols. dipentene to 1 mol butylphenol. Following otherwise the samemethod, a resin is obtained in which again practically the totaldipentene is chemically bound to the butylphenol condensate.

Example 7.-The above procedure may be varied by using a much smallerproportion of strong sulfuric acid but at a higher temperature, namely,around 200 C. A butylphenol resin prepared as in Example 1 from PartsButylphenol 100 40% formaldehyde solution 100 Dipentene and zinc acetatecatalyst is dehydrated as de scribed in the prior'examples, theintermediate product still containing about 5% dissolved freeformaldehyde' The product is treated with an additional 65 parts ofdipentene to bring the dipentene content up to a 1:1 molecular ratiowith reference to the phenol and, after addition of only about 5 partsof strong (96%)sulfuric acid, is heated gradually to about 200 C. Sulfurdioxide is given off during this heating and all the sulfuric acid canbe removed in this way. The formation of S02 is partly due to reactionbetween the dissolved free formaldehyde and the sulfuric acid. Theremoval of the last portions of the sulfuric acid may be hastened bysteam distillation at about 200 C. or above.

Despite the use of strong sulfuric acid at high temperature, no charringtakes place. The resin is pale and oil-soluble. Its acid value is about15-20 and the yield is about 180 grams.

Example 8.-Like Example 7, but in the preparation of thephenol-formaldehyde resin dilute sulfuric acid is used as a catalyst,instead of zinc acetate. After condensation the separated water isremoved and the plastic resin may be more fully dehydrated and furthercondensed by heating in a current of inert gas to about 120 C. Thismaterial is then treated with dipentene and strong sulfuric acid as inExample 7. A similar product is obtained.

The above procedures may be modified in the following manner and stillyield highly satisfactory resins. The terpene material, such asdipentene, terpineol, or pine oil, may first be partially condensed byheating with sulfuric acid. Although higher temperatures may beemployed, I prefer to conduct the heating at about C. for about threehours. In this way a relatively heavy liquid is obtained, but thereaction may, if desired, be conducted until a higher stage ofpolymerization is reached. The sulfuric acid may then be washed out withwater, followed by treatment with an alkaline material to remove tracesof acid, and by further washing; or the liquid may be immediatelyneutralized and then washed with water. In any event, the substantiallyneutral material is dehydrated and then mixed with a dehydratedpartially condensed mixture of a phenol, formaldehyde and a catalyst,such as zinc acetate. If desired, the dehydration of the terpenicpolymer and the phenol-formaldehyde condensate may take place after thetwo materials have been mixed, and the terpene material may be addedwhile it is still acidic, the neutralization and washing of the mixturetaking place after heating together to some extent. The proportions ofthe different materials may correspond to those of any of the aboveexamples. The more or less neutral mixture is now further heated asabove-described, the final heating being preferably at about the boilingpoint of the terpene material or higher until all volatile matter hasbeen expelled. There is obtained a resin which is solid at roomtemperatures and in which is incorporated a relatively large quantityofthe terpene material, the amount being in the neighborhood ofequimolecular proportions with reference to the phenol or mixture ofphenols and even higher.

The resins produced as described hereinabove are soluble in the commonresin solvents including acetone, turpentine, pine oil and itsindividual components, mineral spirits (petroleum distillates), etc; andthey are particularly suitable for the manufacture of oil varnishes asthey are soluble in the drying and non-drying oils, including linseed,China-wood, perilla, sunflower seed, rubberseed, soya bean, cottonseed,fish and other vegetable and animal oils and mixtures thereof. Theresins are preferably condensed to the point at which they are solid atroom temperature, but the reaction may be stopped when the resins areplastic at ordinary temperatures, especially when the proportion ofordinary phenol and formaldehyde is high. The resins 'are suitable forthe manufacture of varnishes, lacquers, paints, etc. and also for theproduction of linoleum compositions by mixture or combination withllnoxyn and similar materials. If desired, the drying or nondryingvegetable oils may be added to the reacting mixture, preferably towardthe close of the reaction, producing oil-modified resins or evenvarnishes, which yield very hard films.

While aluminum halides, zinc chloride and other dehydrating catalystsmay in some instances be employed in place of .sulfuric acid, I havefound the latter to yield the best results.

The phenolic resin to which the terpenic polymer is added may be onethat is either solid or liquid at room temperatures.

In the case of the butyl and amyl phenols above mentioned, the paratertiary compounds are preferred; in the case of cresol, the ortho, metaand para compounds can be used either individually or in admixture.

In general the process is preferably so conducted and the proportion offormaldehyde is made sufllciently large (about 2 mols or more to eachmol of phenol) that after dehydration at about 120 C. the phenoliccondensate contains considerable amounts of free or dissolved or looselybound formaldehyde. Preferably, at least a portion of the terpenecompound is present during the initial condensation of the phenol andformaldehyde, the remainder being added after the dehydration. Thereaction with sulfuric acid can take place either at relatively lowtemperatures (20-'70 0.), in which case larger amounts of acid orstronger acids can be employed; or the reaction may proceed attemperatures up to about. 240 C., in which case smaller amounts of acids(up to about 10% of pure acid based on the amount of phenol) and oflower strength are used. In .the latter instance the sulfuric acid ispractically all destroyed during the reaction, either by evaporationor-by chemical reaction, so that frequently no washing will benecessary, provided only that sufiiclent formaldehyde was present whenthe sulfuric acid was added.

The acid numbers of the resins produced as above described are generallyconsiderably lower than those of similar phenol formaldehyde resinsproduced in the absence of the terpenic material, even after making dueallowance for the diluting effect of the terpenic material. This factindicates that a chemical combination has taken place between the phenolformaldehyde condensate and the terpenic material.

If desired, natural resins or their esters may be employed in the aboveprocess, although they are not necessary for imparting oil-solubility.If rosin is employed, it is desirable to have it present during thesulfuric acid treatment as its acidic quality appears to supplement theaction of the mineral acid.

I claim:

1. The method of producing fusible, water-insoluble phenolic resinswhich are soluble in organic solvents, which comprises condensing aphenol having a substituting alkyl group of at least four carbon atoms,and formaldehyde in the presence of a terpene compound which is normallyliquid and is capable of taking part in the resinification reaction, andof a catalyst, further reacting the terpene-containing mass in thepresence of a sulfuric acid to cause combination between thephenol-formaldehyde condensate and the terpene compound, and heating theproduct so obtained until a still soluble resin is obtained which issolid at room temperature and is substantially free from unreactedmaterial.

2. The method of producing fusible, water-insoluble phenolic resinswhich are soluble in organic solvents, which comprises condensing aphenol and an aldehyde to the intermediate, soluble stage. and reactingthe condensate in the presence of sulfuric acid with a normally liquidterpene compound capable of combining with the condensate.

3. The method of producing fusible, water-insoluble phenolic resinswhich are soluble in organic solvents, which comprises condensing aphenol and formaldehyde to the intermediate. soluble stage, reacting thecondensate in the presence of sulfuric acid with a normally liquidterpene compound capable of combining with the condensate, andthereafter removing the sulfuric acid.

4. The method of producing fusible, water-insoluble phenolic resins.which are soluble in organic solvents, which comprises condensing aphenol and formaldehyde to the intermediate, soluble stage. and reactingthe condensate with dipentene with the aid of sulfuric acid.

5. The method of producing fusible, water-insoluble, phenolic resinswhich are soluble in organic solvents, which comprises condensing aphenol and formaldehyde in the presence of dipentene and of a catalyst,to the intermediate,

a soluble stage, further condensing the dipentenecontaining mass in thepresence of sulfuric acid to cause reaction between the dipentene andthe phenol-formaldehyde condensate, and finally heating the reactionproduct to expel unreacted material until a resin which is substantiallysolid at room temperature but remains soluble in organic solvents isobtained.

6. The method of producing fusible, water-insoluble phenolic resinswhich are soluble in organic solvents, which comprises condensing aphenol and formaldehyde in the presence of an organic zinc compound tothe intermediate, soluble stage, and then reacting the condensate with anormally liquid terpene material consisting primarily of dipentene inthe presence of sulfuric acid.

'7. A fusible resin comprising the reaction product of a soluble,intermediate condensate of a phenol and an aldehyde, and a normallyliquid terpene compound in the presence of sulfuric acid, and producedin accordance with the process of claim 2, said resin being insoluble inwater but soluble in varnish solvents.

8. A fusible resin comprising the reaction product of a soluble.intermediate condensate of a phenol and formaldehyde, and dipentene inthe presence of sulfuric acid-and produced in accordance with theprocess of claim 4.

9. A fusible resin comprising the reaction product of a soluble,intermediate condensate of a phenol and formaldehyde, and an amount of anormally liquid terpene compound approximately equivalent to the weightof phenol, in the presence of sulfuric acid, and produced in accordancewith the process of claim 2, said resin being insoluble in water butsoluble in varnish solvents.

10. A fusible, zinc-containing resin comprising the reaction product ofa soluble, intermediate condensate of a phenol and formaldehyde, and anormally liquid terpene material consisting primarily of dipentene inthe presence of sulfuric acid and produced in accordance with theprocess of claim 6.

ISRAEL ROSENBLUM.

